after 2 weeks of trying to get my ethernet card
(realtek RTL 8139/810x)( with no lights)
to load/boot with knoppix to get on the net
with a cable modem.
and yes searching the net high and low and trying
all that I had found to no avale
I was about to give up wen
I remembered an old trick.

(1)power down the system,
(2)remove the power plug to the back of the computer,
(3) press the power button to drain the computer of all power,
(4)plug the power plug back in to the computer and reboot.
and to my supprize it worked.

if I would have dune this before
it would have saved time
and some if not most of my sanity

this may or may not work for eneyone else
but any thing is worth a try once, right.

PS. you may have to do (1)-(4) every time
you boot from windows to linux
to get linux on the net.
but not from linux boot to linux boot.
this is the way it has ben working for me
for all builds of linux.